Soil fauna increase nitrogen loss in tilled soil with legume but reduce nitrogen loss in non-tilled soil without legume

► Soil fauna affect N dynamics differently in tilled vs. no-till systems. ► Soil fauna increased N loss from the tilled soil with legume, but reduced N loss in non-tilled soil without legume. ► Soil fauna also increased bacterial biomass in tilled soil with legume, but not in non-tilled soil without legume. ► Soil bacterial and fungal communities differed by the tillage and legumes. ► Non-tilled soil with fauna can conserve soil N and enhance the efficient use of N by plants.